1. Field of the Invention
This invention relates to the use of clad/sheathed or unclad/unsheathed optical fibre(s) with ultra violet (U.V.) and/or infra-red (I.R.) radiation sensors to form line or spot fire and/or heat detectors.
There are three aspects of the invention. In the first, the fibre(s) is left unclad/unsheathed, or sheathed with a transparent material, such that ultra violet radiation in the vicinity of the fibre(s) passes through the fibre(s) skin into its body. The ultra violet radiation once inside the body of the fibre is transmitted to the ends of the fibre(s) by the natural physical characteristics of optical fibre(s). Use is made of this natural characteristic to extend the viewing of special or standard commercially available U.V. Fire Detectors, to overcome certain defects inherent with this type of detector.
2. Description of the Prior Art
Commercially, Fire Detectors tuned to U.V. radiation are installed in fire risk areas to monitor for flames created by a fire in those areas. The flames radiate U.V. radiation which is collected by the Detector viewing window. All such detectors suffer a common fault of only being able to view in a straight line and this line of vision must be unobstructed. This places limitations upon the usage of fire detectors of this kind and limitations upon the customer when they are used. In the invention now being described these defects are overcome by using an optical fibre to extend, shape or bend the viewing angle in order to extend the radiation collecting ability of the U.V. Flame Detector.